1. Field of the Invention
This invention relates to a device that continuously measures and displays the speed of a vehicle on a digital readout display located in the vicinity of the vehicle's dashboard. A desired speed is set on a separate digital switch integrated into the circuitry of the device. A plurality of comparators continually compare the set speed with the vehicle's actual speed. As the vehicle's actual speed exceeds the set speed, a buzzer sounds and/or the speed display in the vicinity of the dashboard flashes on and off to alert the driver that he or she has exceeded the set speed. When the vehicle's speed decreases and its speed falls below the set speed, the buzzer and/or flashing display stops and the device acts as a regular digital speedometer.
The signals of the device which indicate vehicle speed are adjustable, thus enabling the device to be adaptable for use on a wide variety of vehicles. For example, the device may be used on motor vehicles such as automobiles, trucks, motorcycles, vehicles such as bicycles or any other vehicle which utilizes a wheel and/or a shaft, e.g., a drive shaft.
Currently most motor vehicles are equipped with a pointer type speedometer to determine the speed of a vehicle. These standard type speedometers normally contain numbers from 0 to about 100 which represent the speed of the vehicle in either miles per hour (MPH) or kilometers per hour (Km/hr). A section of the standard speedometer is usually marked in red, normally at a speed of 55 or above to alert the driver that he or she is exceeding the legal speed limit. This type speedometer system suffers from the disadvantage that requires the driver of the vehicle to periodically glance at the speedometer to check the vehicle speed. This problem creates a potential driving hazard because the driver is not looking at the roadway and observing the driving conditions in the vicinity of the vehicle, including stop signs and lights, other vehicles, etc.
More recently, the automotive industry has installed digital speedometers in a selected few of their vehicles. These digital speedometers suffer from the same disadvantages accorded to the pointer type speedometers, because they are not equipped to alert the driver when the vehicle speed surpasses a pre-set, desired upper speed.
The instant, Speed Minder, solves the above-described problems by alerting the vehicle driver when the vehicle exceeds a pre-determined upper speed limit.
As can be determined from the foregoing, there is a need for a device that will physically alert a driver of a vehicle that the vehicle is exceeding a pre-determined speed limit, e.g., by an audible alarm and/or flashing lights on the digital read-out panel.
2. Description of the Prior Art
Several attempts have been made in the past to develop speed sensing devices for motor vehicles and devices to alert the driver of a motor vehicle when the vehicle exceeds a pre-determined speed.
For example, U.S. Pat. No. 3,728,565 to O'Callaghan, relates to a device for sensing the direction of rotation and the speed of a shaft. The device includes a two-phase AC generator having a rotor attachable to a shaft and rotatable therewith and a first and second spaced apart starter winding which are adapted to have first and second sinusoidal voltages established in response to rotation of the rotor with the shaft.
U.S. Pat. No. 4,142,152 to Fincher discloses a directional sensing apparatus containing a rotatable member having a plurality of permanent magnets which magnetically influence a first and second spaced stationary sensor. The rotation of the member causes the magnets to sequentially operate the first and second sensors so that neither, either or both are actuated.
U.S. Pat. No. 4,143,352 to Joarmatz describes an audible speed indicator for motor vehicles which contains two pulse trains, one of which varies as a function of vehicle speed and the other which varies as a function of a desired speed which is manually set. When the actual speed increases to a value greater than the set speed an audio alarm sounds.
U.S. Pat. No. 4,200,816 to Hopkins relates to a wheel speed sensor which is described as suitable for sensing the angular velocity of a rotating body such as a vehicle wheel. The device contains a sensing device which requires only a single coil for generating an electrical signal through said coil. The rotation sensor provides an output signal suitable for use in an anti-lock system on a motor vehicle.
U.S. Pat. No. 4,223,297 to Nomura et al discloses a speed alarm system for a motor vehicle which consists of a speed sensor, a plurality of comparators responsive to the vehicle speed and a pre-set speed. When the vehicle speed exceeds a pre-set speed an alarm signal step wise energizes a number of lamps in accordance with the difference between the vehicle speed and the pre-set speed.
U.S. Pat. No. 4,371,864 to Kawasaki et al discloses a digital display device which is described as suitable for controlling other vehicle mounted electric equipment such as a warning device, Automatic door lock, etc.
U.S. Pat. No. 5,086,272 to Hinricksen relates to a motion-direction detector utilizing passive magnetic induction sensors. The sensors are disposed adjacent to the path of magnetic variations of a moving part to determine the motion-direction of said part.
As can readily be determined from the foregoing, there is an ongoing research effort to produce new and novel devices to determine the speed of moving objects, for example, motor vehicles, and to provide the vehicle operators with a type of alarm or the like for said vehicle.